1 //===-- sanitizer_linux.cpp -----------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is shared between AddressSanitizer and ThreadSanitizer 10 // run-time libraries and implements linux-specific functions from 11 // sanitizer_libc.h. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 17 SANITIZER_SOLARIS 18 19 #include "sanitizer_common.h" 20 #include "sanitizer_flags.h" 21 #include "sanitizer_getauxval.h" 22 #include "sanitizer_internal_defs.h" 23 #include "sanitizer_libc.h" 24 #include "sanitizer_linux.h" 25 #include "sanitizer_mutex.h" 26 #include "sanitizer_placement_new.h" 27 #include "sanitizer_procmaps.h" 28 29 #if SANITIZER_LINUX && !SANITIZER_GO 30 #include <asm/param.h> 31 #endif 32 33 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat' 34 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To 35 // access stat from asm/stat.h, without conflicting with definition in 36 // sys/stat.h, we use this trick. 37 #if SANITIZER_LINUX 38 #if defined(__mips64) 39 #include <asm/unistd.h> 40 #include <sys/types.h> 41 #define stat kernel_stat 42 #if SANITIZER_GO 43 #undef st_atime 44 #undef st_mtime 45 #undef st_ctime 46 #define st_atime st_atim 47 #define st_mtime st_mtim 48 #define st_ctime st_ctim 49 #endif 50 #include <asm/stat.h> 51 #undef stat 52 #endif 53 #endif 54 55 #if SANITIZER_NETBSD 56 #include <lwp.h> 57 #endif 58 59 #include <dlfcn.h> 60 #include <errno.h> 61 #include <fcntl.h> 62 #include <link.h> 63 #include <pthread.h> 64 #include <sched.h> 65 #include <signal.h> 66 #include <sys/mman.h> 67 #include <sys/param.h> 68 #if !SANITIZER_SOLARIS 69 #include <sys/ptrace.h> 70 #endif 71 #include <sys/resource.h> 72 #include <sys/stat.h> 73 #include <sys/syscall.h> 74 #include <sys/time.h> 75 #include <sys/types.h> 76 #include <ucontext.h> 77 #include <unistd.h> 78 79 #if SANITIZER_LINUX 80 #include <sys/utsname.h> 81 #endif 82 83 #if SANITIZER_LINUX && !SANITIZER_ANDROID 84 #include <sys/personality.h> 85 #endif 86 87 #if SANITIZER_FREEBSD 88 #include <sys/exec.h> 89 #include <sys/sysctl.h> 90 #include <machine/atomic.h> 91 extern "C" { 92 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on 93 // FreeBSD 9.2 and 10.0. 94 #include <sys/umtx.h> 95 } 96 #include <sys/thr.h> 97 #endif // SANITIZER_FREEBSD 98 99 #if SANITIZER_NETBSD 100 #include <limits.h> // For NAME_MAX 101 #include <sys/sysctl.h> 102 #include <sys/exec.h> 103 extern struct ps_strings *__ps_strings; 104 #endif // SANITIZER_NETBSD 105 106 #if SANITIZER_SOLARIS 107 #include <stdlib.h> 108 #include <thread.h> 109 #define environ _environ 110 #endif 111 112 extern char **environ; 113 114 #if SANITIZER_LINUX 115 // <linux/time.h> 116 struct kernel_timeval { 117 long tv_sec; 118 long tv_usec; 119 }; 120 121 // <linux/futex.h> is broken on some linux distributions. 122 const int FUTEX_WAIT = 0; 123 const int FUTEX_WAKE = 1; 124 const int FUTEX_PRIVATE_FLAG = 128; 125 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG; 126 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG; 127 #endif // SANITIZER_LINUX 128 129 // Are we using 32-bit or 64-bit Linux syscalls? 130 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32 131 // but it still needs to use 64-bit syscalls. 132 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \ 133 SANITIZER_WORDSIZE == 64) 134 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1 135 #else 136 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0 137 #endif 138 139 // Note : FreeBSD had implemented both 140 // Linux apis, available from 141 // future 12.x version most likely 142 #if SANITIZER_LINUX && defined(__NR_getrandom) 143 # if !defined(GRND_NONBLOCK) 144 # define GRND_NONBLOCK 1 145 # endif 146 # define SANITIZER_USE_GETRANDOM 1 147 #else 148 # define SANITIZER_USE_GETRANDOM 0 149 #endif // SANITIZER_LINUX && defined(__NR_getrandom) 150 151 #if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000 152 # define SANITIZER_USE_GETENTROPY 1 153 #else 154 # define SANITIZER_USE_GETENTROPY 0 155 #endif 156 157 namespace __sanitizer { 158 159 void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *old) { 160 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, set, old)); 161 } 162 163 ScopedBlockSignals::ScopedBlockSignals(__sanitizer_sigset_t *copy) { 164 __sanitizer_sigset_t set; 165 internal_sigfillset(&set); 166 # if SANITIZER_LINUX && !SANITIZER_ANDROID 167 // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked 168 // on any thread, setuid call hangs. 169 // See test/sanitizer_common/TestCases/Linux/setuid.c. 170 internal_sigdelset(&set, 33); 171 # endif 172 SetSigProcMask(&set, &saved_); 173 if (copy) 174 internal_memcpy(copy, &saved_, sizeof(saved_)); 175 } 176 177 ScopedBlockSignals::~ScopedBlockSignals() { SetSigProcMask(&saved_, nullptr); } 178 179 # if SANITIZER_LINUX && defined(__x86_64__) 180 # include "sanitizer_syscall_linux_x86_64.inc" 181 # elif SANITIZER_LINUX && SANITIZER_RISCV64 182 # include "sanitizer_syscall_linux_riscv64.inc" 183 # elif SANITIZER_LINUX && defined(__aarch64__) 184 # include "sanitizer_syscall_linux_aarch64.inc" 185 # elif SANITIZER_LINUX && defined(__arm__) 186 # include "sanitizer_syscall_linux_arm.inc" 187 # elif SANITIZER_LINUX && defined(__hexagon__) 188 # include "sanitizer_syscall_linux_hexagon.inc" 189 # else 190 # include "sanitizer_syscall_generic.inc" 191 # endif 192 193 // --------------- sanitizer_libc.h 194 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 195 #if !SANITIZER_S390 196 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd, 197 u64 offset) { 198 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS 199 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd, 200 offset); 201 #else 202 // mmap2 specifies file offset in 4096-byte units. 203 CHECK(IsAligned(offset, 4096)); 204 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd, 205 offset / 4096); 206 #endif 207 } 208 #endif // !SANITIZER_S390 209 210 uptr internal_munmap(void *addr, uptr length) { 211 return internal_syscall(SYSCALL(munmap), (uptr)addr, length); 212 } 213 214 #if SANITIZER_LINUX 215 uptr internal_mremap(void *old_address, uptr old_size, uptr new_size, int flags, 216 void *new_address) { 217 return internal_syscall(SYSCALL(mremap), (uptr)old_address, old_size, 218 new_size, flags, (uptr)new_address); 219 } 220 #endif 221 222 int internal_mprotect(void *addr, uptr length, int prot) { 223 return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot); 224 } 225 226 int internal_madvise(uptr addr, uptr length, int advice) { 227 return internal_syscall(SYSCALL(madvise), addr, length, advice); 228 } 229 230 uptr internal_close(fd_t fd) { 231 return internal_syscall(SYSCALL(close), fd); 232 } 233 234 uptr internal_open(const char *filename, int flags) { 235 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 236 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags); 237 #else 238 return internal_syscall(SYSCALL(open), (uptr)filename, flags); 239 #endif 240 } 241 242 uptr internal_open(const char *filename, int flags, u32 mode) { 243 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 244 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags, 245 mode); 246 #else 247 return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode); 248 #endif 249 } 250 251 uptr internal_read(fd_t fd, void *buf, uptr count) { 252 sptr res; 253 HANDLE_EINTR(res, 254 (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count)); 255 return res; 256 } 257 258 uptr internal_write(fd_t fd, const void *buf, uptr count) { 259 sptr res; 260 HANDLE_EINTR(res, 261 (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count)); 262 return res; 263 } 264 265 uptr internal_ftruncate(fd_t fd, uptr size) { 266 sptr res; 267 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd, 268 (OFF_T)size)); 269 return res; 270 } 271 272 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX 273 static void stat64_to_stat(struct stat64 *in, struct stat *out) { 274 internal_memset(out, 0, sizeof(*out)); 275 out->st_dev = in->st_dev; 276 out->st_ino = in->st_ino; 277 out->st_mode = in->st_mode; 278 out->st_nlink = in->st_nlink; 279 out->st_uid = in->st_uid; 280 out->st_gid = in->st_gid; 281 out->st_rdev = in->st_rdev; 282 out->st_size = in->st_size; 283 out->st_blksize = in->st_blksize; 284 out->st_blocks = in->st_blocks; 285 out->st_atime = in->st_atime; 286 out->st_mtime = in->st_mtime; 287 out->st_ctime = in->st_ctime; 288 } 289 #endif 290 291 #if defined(__mips64) 292 // Undefine compatibility macros from <sys/stat.h> 293 // so that they would not clash with the kernel_stat 294 // st_[a|m|c]time fields 295 #if !SANITIZER_GO 296 #undef st_atime 297 #undef st_mtime 298 #undef st_ctime 299 #endif 300 #if defined(SANITIZER_ANDROID) 301 // Bionic sys/stat.h defines additional macros 302 // for compatibility with the old NDKs and 303 // they clash with the kernel_stat structure 304 // st_[a|m|c]time_nsec fields. 305 #undef st_atime_nsec 306 #undef st_mtime_nsec 307 #undef st_ctime_nsec 308 #endif 309 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) { 310 internal_memset(out, 0, sizeof(*out)); 311 out->st_dev = in->st_dev; 312 out->st_ino = in->st_ino; 313 out->st_mode = in->st_mode; 314 out->st_nlink = in->st_nlink; 315 out->st_uid = in->st_uid; 316 out->st_gid = in->st_gid; 317 out->st_rdev = in->st_rdev; 318 out->st_size = in->st_size; 319 out->st_blksize = in->st_blksize; 320 out->st_blocks = in->st_blocks; 321 #if defined(__USE_MISC) || \ 322 defined(__USE_XOPEN2K8) || \ 323 defined(SANITIZER_ANDROID) 324 out->st_atim.tv_sec = in->st_atime; 325 out->st_atim.tv_nsec = in->st_atime_nsec; 326 out->st_mtim.tv_sec = in->st_mtime; 327 out->st_mtim.tv_nsec = in->st_mtime_nsec; 328 out->st_ctim.tv_sec = in->st_ctime; 329 out->st_ctim.tv_nsec = in->st_ctime_nsec; 330 #else 331 out->st_atime = in->st_atime; 332 out->st_atimensec = in->st_atime_nsec; 333 out->st_mtime = in->st_mtime; 334 out->st_mtimensec = in->st_mtime_nsec; 335 out->st_ctime = in->st_ctime; 336 out->st_atimensec = in->st_ctime_nsec; 337 #endif 338 } 339 #endif 340 341 uptr internal_stat(const char *path, void *buf) { 342 #if SANITIZER_FREEBSD 343 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0); 344 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 345 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 346 0); 347 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS 348 # if defined(__mips64) 349 // For mips64, stat syscall fills buffer in the format of kernel_stat 350 struct kernel_stat kbuf; 351 int res = internal_syscall(SYSCALL(stat), path, &kbuf); 352 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 353 return res; 354 # else 355 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf); 356 # endif 357 #else 358 struct stat64 buf64; 359 int res = internal_syscall(SYSCALL(stat64), path, &buf64); 360 stat64_to_stat(&buf64, (struct stat *)buf); 361 return res; 362 #endif 363 } 364 365 uptr internal_lstat(const char *path, void *buf) { 366 #if SANITIZER_FREEBSD 367 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 368 AT_SYMLINK_NOFOLLOW); 369 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 370 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 371 AT_SYMLINK_NOFOLLOW); 372 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS 373 # if SANITIZER_MIPS64 374 // For mips64, lstat syscall fills buffer in the format of kernel_stat 375 struct kernel_stat kbuf; 376 int res = internal_syscall(SYSCALL(lstat), path, &kbuf); 377 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 378 return res; 379 # else 380 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf); 381 # endif 382 #else 383 struct stat64 buf64; 384 int res = internal_syscall(SYSCALL(lstat64), path, &buf64); 385 stat64_to_stat(&buf64, (struct stat *)buf); 386 return res; 387 #endif 388 } 389 390 uptr internal_fstat(fd_t fd, void *buf) { 391 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS 392 #if SANITIZER_MIPS64 393 // For mips64, fstat syscall fills buffer in the format of kernel_stat 394 struct kernel_stat kbuf; 395 int res = internal_syscall(SYSCALL(fstat), fd, &kbuf); 396 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 397 return res; 398 # else 399 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf); 400 # endif 401 #else 402 struct stat64 buf64; 403 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64); 404 stat64_to_stat(&buf64, (struct stat *)buf); 405 return res; 406 #endif 407 } 408 409 uptr internal_filesize(fd_t fd) { 410 struct stat st; 411 if (internal_fstat(fd, &st)) 412 return -1; 413 return (uptr)st.st_size; 414 } 415 416 uptr internal_dup(int oldfd) { 417 return internal_syscall(SYSCALL(dup), oldfd); 418 } 419 420 uptr internal_dup2(int oldfd, int newfd) { 421 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 422 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0); 423 #else 424 return internal_syscall(SYSCALL(dup2), oldfd, newfd); 425 #endif 426 } 427 428 uptr internal_readlink(const char *path, char *buf, uptr bufsize) { 429 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 430 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf, 431 bufsize); 432 #else 433 return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize); 434 #endif 435 } 436 437 uptr internal_unlink(const char *path) { 438 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 439 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0); 440 #else 441 return internal_syscall(SYSCALL(unlink), (uptr)path); 442 #endif 443 } 444 445 uptr internal_rename(const char *oldpath, const char *newpath) { 446 #if defined(__riscv) && defined(__linux__) 447 return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD, 448 (uptr)newpath, 0); 449 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 450 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD, 451 (uptr)newpath); 452 #else 453 return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath); 454 #endif 455 } 456 457 uptr internal_sched_yield() { 458 return internal_syscall(SYSCALL(sched_yield)); 459 } 460 461 void internal_usleep(u64 useconds) { 462 struct timespec ts; 463 ts.tv_sec = useconds / 1000000; 464 ts.tv_nsec = (useconds % 1000000) * 1000; 465 internal_syscall(SYSCALL(nanosleep), &ts, &ts); 466 } 467 468 uptr internal_execve(const char *filename, char *const argv[], 469 char *const envp[]) { 470 return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv, 471 (uptr)envp); 472 } 473 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD 474 475 #if !SANITIZER_NETBSD 476 void internal__exit(int exitcode) { 477 #if SANITIZER_FREEBSD || SANITIZER_SOLARIS 478 internal_syscall(SYSCALL(exit), exitcode); 479 #else 480 internal_syscall(SYSCALL(exit_group), exitcode); 481 #endif 482 Die(); // Unreachable. 483 } 484 #endif // !SANITIZER_NETBSD 485 486 // ----------------- sanitizer_common.h 487 bool FileExists(const char *filename) { 488 if (ShouldMockFailureToOpen(filename)) 489 return false; 490 struct stat st; 491 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 492 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0)) 493 #else 494 if (internal_stat(filename, &st)) 495 #endif 496 return false; 497 // Sanity check: filename is a regular file. 498 return S_ISREG(st.st_mode); 499 } 500 501 #if !SANITIZER_NETBSD 502 tid_t GetTid() { 503 #if SANITIZER_FREEBSD 504 long Tid; 505 thr_self(&Tid); 506 return Tid; 507 #elif SANITIZER_SOLARIS 508 return thr_self(); 509 #else 510 return internal_syscall(SYSCALL(gettid)); 511 #endif 512 } 513 514 int TgKill(pid_t pid, tid_t tid, int sig) { 515 #if SANITIZER_LINUX 516 return internal_syscall(SYSCALL(tgkill), pid, tid, sig); 517 #elif SANITIZER_FREEBSD 518 return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig); 519 #elif SANITIZER_SOLARIS 520 (void)pid; 521 return thr_kill(tid, sig); 522 #endif 523 } 524 #endif 525 526 #if SANITIZER_GLIBC 527 u64 NanoTime() { 528 kernel_timeval tv; 529 internal_memset(&tv, 0, sizeof(tv)); 530 internal_syscall(SYSCALL(gettimeofday), &tv, 0); 531 return (u64)tv.tv_sec * 1000 * 1000 * 1000 + tv.tv_usec * 1000; 532 } 533 // Used by real_clock_gettime. 534 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) { 535 return internal_syscall(SYSCALL(clock_gettime), clk_id, tp); 536 } 537 #elif !SANITIZER_SOLARIS && !SANITIZER_NETBSD 538 u64 NanoTime() { 539 struct timespec ts; 540 clock_gettime(CLOCK_REALTIME, &ts); 541 return (u64)ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec; 542 } 543 #endif 544 545 // Like getenv, but reads env directly from /proc (on Linux) or parses the 546 // 'environ' array (on some others) and does not use libc. This function 547 // should be called first inside __asan_init. 548 const char *GetEnv(const char *name) { 549 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_SOLARIS 550 if (::environ != 0) { 551 uptr NameLen = internal_strlen(name); 552 for (char **Env = ::environ; *Env != 0; Env++) { 553 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=') 554 return (*Env) + NameLen + 1; 555 } 556 } 557 return 0; // Not found. 558 #elif SANITIZER_LINUX 559 static char *environ; 560 static uptr len; 561 static bool inited; 562 if (!inited) { 563 inited = true; 564 uptr environ_size; 565 if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len)) 566 environ = nullptr; 567 } 568 if (!environ || len == 0) return nullptr; 569 uptr namelen = internal_strlen(name); 570 const char *p = environ; 571 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer 572 // proc file has the format NAME=value\0NAME=value\0NAME=value\0... 573 const char* endp = 574 (char*)internal_memchr(p, '\0', len - (p - environ)); 575 if (!endp) // this entry isn't NUL terminated 576 return nullptr; 577 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match. 578 return p + namelen + 1; // point after = 579 p = endp + 1; 580 } 581 return nullptr; // Not found. 582 #else 583 #error "Unsupported platform" 584 #endif 585 } 586 587 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_GO 588 extern "C" { 589 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end; 590 } 591 #endif 592 593 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD 594 static void ReadNullSepFileToArray(const char *path, char ***arr, 595 int arr_size) { 596 char *buff; 597 uptr buff_size; 598 uptr buff_len; 599 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray"); 600 if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) { 601 (*arr)[0] = nullptr; 602 return; 603 } 604 (*arr)[0] = buff; 605 int count, i; 606 for (count = 1, i = 1; ; i++) { 607 if (buff[i] == 0) { 608 if (buff[i+1] == 0) break; 609 (*arr)[count] = &buff[i+1]; 610 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible. 611 count++; 612 } 613 } 614 (*arr)[count] = nullptr; 615 } 616 #endif 617 618 #if SANITIZER_NETBSD 619 static char ** 620 load_vector(int m) 621 { 622 size_t size; 623 int nv; 624 char **v, **ap, *bp, *buf, *endp; 625 int mib[4] = {CTL_KERN, KERN_PROC_ARGS, getpid(), 0}; 626 size = sizeof(nv); 627 mib[3] = m == KERN_PROC_ARGV ? KERN_PROC_NARGV : KERN_PROC_NENV; 628 if (internal_sysctl(mib, 4, &nv, &size, NULL, 0) == -1) { 629 Printf("sysctl KERN_PROC_N{ARGV,ENV} failed\n"); 630 Die(); 631 } 632 v = (char **)MmapOrDie((nv + 1) * sizeof(char *), "Arg vector"); 633 buf = (char *)MmapOrDie(ARG_MAX, "Arg space"); 634 size = ARG_MAX; 635 mib[3] = m; 636 if (internal_sysctl(mib, 4, buf, &size, NULL, 0) == -1) { 637 Printf("sysctl KERN_PROC_{ARGV,ENV} failed\n"); 638 Die(); 639 } 640 bp = buf; 641 ap = v; 642 endp = bp + size; 643 644 while (bp < endp) { 645 *ap++ = bp; 646 bp += internal_strlen(bp) + 1; 647 } 648 *ap = NULL; 649 return v; 650 } 651 #endif 652 653 static void GetArgsAndEnv(char ***argv, char ***envp) { 654 #if SANITIZER_FREEBSD 655 // On FreeBSD, retrieving the argument and environment arrays is done via the 656 // kern.ps_strings sysctl, which returns a pointer to a structure containing 657 // this information. See also <sys/exec.h>. 658 ps_strings *pss; 659 uptr sz = sizeof(pss); 660 if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) { 661 Printf("sysctl kern.ps_strings failed\n"); 662 Die(); 663 } 664 *argv = pss->ps_argvstr; 665 *envp = pss->ps_envstr; 666 #elif SANITIZER_NETBSD 667 *argv = load_vector(KERN_PROC_ARGV); 668 *envp = load_vector(KERN_PROC_ENV); 669 #else // SANITIZER_FREEBSD 670 #if !SANITIZER_GO 671 if (&__libc_stack_end) { 672 uptr* stack_end = (uptr*)__libc_stack_end; 673 // Normally argc can be obtained from *stack_end, however, on ARM glibc's 674 // _start clobbers it: 675 // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/arm/start.S;hb=refs/heads/release/2.31/master#l75 676 // Do not special-case ARM and infer argc from argv everywhere. 677 int argc = 0; 678 while (stack_end[argc + 1]) argc++; 679 *argv = (char**)(stack_end + 1); 680 *envp = (char**)(stack_end + argc + 2); 681 } else { 682 #endif // !SANITIZER_GO 683 static const int kMaxArgv = 2000, kMaxEnvp = 2000; 684 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv); 685 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp); 686 #if !SANITIZER_GO 687 } 688 #endif // !SANITIZER_GO 689 #endif // SANITIZER_FREEBSD 690 } 691 692 char **GetArgv() { 693 char **argv, **envp; 694 GetArgsAndEnv(&argv, &envp); 695 return argv; 696 } 697 698 char **GetEnviron() { 699 char **argv, **envp; 700 GetArgsAndEnv(&argv, &envp); 701 return envp; 702 } 703 704 #if !SANITIZER_SOLARIS 705 void FutexWait(atomic_uint32_t *p, u32 cmp) { 706 # if SANITIZER_FREEBSD 707 _umtx_op(p, UMTX_OP_WAIT_UINT, cmp, 0, 0); 708 # elif SANITIZER_NETBSD 709 sched_yield(); /* No userspace futex-like synchronization */ 710 # else 711 internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAIT_PRIVATE, cmp, 0, 0, 0); 712 # endif 713 } 714 715 void FutexWake(atomic_uint32_t *p, u32 count) { 716 # if SANITIZER_FREEBSD 717 _umtx_op(p, UMTX_OP_WAKE, count, 0, 0); 718 # elif SANITIZER_NETBSD 719 /* No userspace futex-like synchronization */ 720 # else 721 internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAKE_PRIVATE, count, 0, 0, 0); 722 # endif 723 } 724 725 # endif // !SANITIZER_SOLARIS 726 727 // ----------------- sanitizer_linux.h 728 // The actual size of this structure is specified by d_reclen. 729 // Note that getdents64 uses a different structure format. We only provide the 730 // 32-bit syscall here. 731 #if SANITIZER_NETBSD 732 // Not used 733 #else 734 struct linux_dirent { 735 #if SANITIZER_X32 || defined(__aarch64__) || SANITIZER_RISCV64 736 u64 d_ino; 737 u64 d_off; 738 #else 739 unsigned long d_ino; 740 unsigned long d_off; 741 #endif 742 unsigned short d_reclen; 743 #if defined(__aarch64__) || SANITIZER_RISCV64 744 unsigned char d_type; 745 #endif 746 char d_name[256]; 747 }; 748 #endif 749 750 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 751 // Syscall wrappers. 752 uptr internal_ptrace(int request, int pid, void *addr, void *data) { 753 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr, 754 (uptr)data); 755 } 756 757 uptr internal_waitpid(int pid, int *status, int options) { 758 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options, 759 0 /* rusage */); 760 } 761 762 uptr internal_getpid() { 763 return internal_syscall(SYSCALL(getpid)); 764 } 765 766 uptr internal_getppid() { 767 return internal_syscall(SYSCALL(getppid)); 768 } 769 770 int internal_dlinfo(void *handle, int request, void *p) { 771 #if SANITIZER_FREEBSD 772 return dlinfo(handle, request, p); 773 #else 774 UNIMPLEMENTED(); 775 #endif 776 } 777 778 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) { 779 #if SANITIZER_FREEBSD 780 return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL); 781 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 782 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count); 783 #else 784 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count); 785 #endif 786 } 787 788 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) { 789 return internal_syscall(SYSCALL(lseek), fd, offset, whence); 790 } 791 792 #if SANITIZER_LINUX 793 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) { 794 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5); 795 } 796 #endif 797 798 uptr internal_sigaltstack(const void *ss, void *oss) { 799 return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss); 800 } 801 802 int internal_fork() { 803 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 804 return internal_syscall(SYSCALL(clone), SIGCHLD, 0); 805 #else 806 return internal_syscall(SYSCALL(fork)); 807 #endif 808 } 809 810 #if SANITIZER_FREEBSD 811 int internal_sysctl(const int *name, unsigned int namelen, void *oldp, 812 uptr *oldlenp, const void *newp, uptr newlen) { 813 return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp, 814 (size_t *)oldlenp, newp, (size_t)newlen); 815 } 816 817 int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp, 818 const void *newp, uptr newlen) { 819 // Note: this function can be called during startup, so we need to avoid 820 // calling any interceptable functions. On FreeBSD >= 1300045 sysctlbyname() 821 // is a real syscall, but for older versions it calls sysctlnametomib() 822 // followed by sysctl(). To avoid calling the intercepted version and 823 // asserting if this happens during startup, call the real sysctlnametomib() 824 // followed by internal_sysctl() if the syscall is not available. 825 #ifdef SYS___sysctlbyname 826 return internal_syscall(SYSCALL(__sysctlbyname), sname, 827 internal_strlen(sname), oldp, (size_t *)oldlenp, newp, 828 (size_t)newlen); 829 #else 830 static decltype(sysctlnametomib) *real_sysctlnametomib = nullptr; 831 if (!real_sysctlnametomib) 832 real_sysctlnametomib = 833 (decltype(sysctlnametomib) *)dlsym(RTLD_NEXT, "sysctlnametomib"); 834 CHECK(real_sysctlnametomib); 835 836 int oid[CTL_MAXNAME]; 837 size_t len = CTL_MAXNAME; 838 if (real_sysctlnametomib(sname, oid, &len) == -1) 839 return (-1); 840 return internal_sysctl(oid, len, oldp, oldlenp, newp, newlen); 841 #endif 842 } 843 #endif 844 845 #if SANITIZER_LINUX 846 #define SA_RESTORER 0x04000000 847 // Doesn't set sa_restorer if the caller did not set it, so use with caution 848 //(see below). 849 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) { 850 __sanitizer_kernel_sigaction_t k_act, k_oldact; 851 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t)); 852 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t)); 853 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act; 854 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact; 855 if (u_act) { 856 k_act.handler = u_act->handler; 857 k_act.sigaction = u_act->sigaction; 858 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask, 859 sizeof(__sanitizer_kernel_sigset_t)); 860 // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL). 861 k_act.sa_flags = u_act->sa_flags | SA_RESTORER; 862 // FIXME: most often sa_restorer is unset, however the kernel requires it 863 // to point to a valid signal restorer that calls the rt_sigreturn syscall. 864 // If sa_restorer passed to the kernel is NULL, the program may crash upon 865 // signal delivery or fail to unwind the stack in the signal handler. 866 // libc implementation of sigaction() passes its own restorer to 867 // rt_sigaction, so we need to do the same (we'll need to reimplement the 868 // restorers; for x86_64 the restorer address can be obtained from 869 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact). 870 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 871 k_act.sa_restorer = u_act->sa_restorer; 872 #endif 873 } 874 875 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum, 876 (uptr)(u_act ? &k_act : nullptr), 877 (uptr)(u_oldact ? &k_oldact : nullptr), 878 (uptr)sizeof(__sanitizer_kernel_sigset_t)); 879 880 if ((result == 0) && u_oldact) { 881 u_oldact->handler = k_oldact.handler; 882 u_oldact->sigaction = k_oldact.sigaction; 883 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask, 884 sizeof(__sanitizer_kernel_sigset_t)); 885 u_oldact->sa_flags = k_oldact.sa_flags; 886 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 887 u_oldact->sa_restorer = k_oldact.sa_restorer; 888 #endif 889 } 890 return result; 891 } 892 #endif // SANITIZER_LINUX 893 894 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, 895 __sanitizer_sigset_t *oldset) { 896 #if SANITIZER_FREEBSD 897 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset); 898 #else 899 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 900 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset; 901 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how, (uptr)k_set, 902 (uptr)k_oldset, sizeof(__sanitizer_kernel_sigset_t)); 903 #endif 904 } 905 906 void internal_sigfillset(__sanitizer_sigset_t *set) { 907 internal_memset(set, 0xff, sizeof(*set)); 908 } 909 910 void internal_sigemptyset(__sanitizer_sigset_t *set) { 911 internal_memset(set, 0, sizeof(*set)); 912 } 913 914 #if SANITIZER_LINUX 915 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { 916 signum -= 1; 917 CHECK_GE(signum, 0); 918 CHECK_LT(signum, sizeof(*set) * 8); 919 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 920 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8); 921 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8); 922 k_set->sig[idx] &= ~((uptr)1 << bit); 923 } 924 925 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) { 926 signum -= 1; 927 CHECK_GE(signum, 0); 928 CHECK_LT(signum, sizeof(*set) * 8); 929 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 930 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8); 931 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8); 932 return k_set->sig[idx] & ((uptr)1 << bit); 933 } 934 #elif SANITIZER_FREEBSD 935 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { 936 sigset_t *rset = reinterpret_cast<sigset_t *>(set); 937 sigdelset(rset, signum); 938 } 939 940 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) { 941 sigset_t *rset = reinterpret_cast<sigset_t *>(set); 942 return sigismember(rset, signum); 943 } 944 #endif 945 #endif // !SANITIZER_SOLARIS 946 947 #if !SANITIZER_NETBSD 948 // ThreadLister implementation. 949 ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) { 950 char task_directory_path[80]; 951 internal_snprintf(task_directory_path, sizeof(task_directory_path), 952 "/proc/%d/task/", pid); 953 descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY); 954 if (internal_iserror(descriptor_)) { 955 Report("Can't open /proc/%d/task for reading.\n", pid); 956 } 957 } 958 959 ThreadLister::Result ThreadLister::ListThreads( 960 InternalMmapVector<tid_t> *threads) { 961 if (internal_iserror(descriptor_)) 962 return Error; 963 internal_lseek(descriptor_, 0, SEEK_SET); 964 threads->clear(); 965 966 Result result = Ok; 967 for (bool first_read = true;; first_read = false) { 968 // Resize to max capacity if it was downsized by IsAlive. 969 buffer_.resize(buffer_.capacity()); 970 CHECK_GE(buffer_.size(), 4096); 971 uptr read = internal_getdents( 972 descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size()); 973 if (!read) 974 return result; 975 if (internal_iserror(read)) { 976 Report("Can't read directory entries from /proc/%d/task.\n", pid_); 977 return Error; 978 } 979 980 for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) { 981 struct linux_dirent *entry = (struct linux_dirent *)begin; 982 begin += entry->d_reclen; 983 if (entry->d_ino == 1) { 984 // Inode 1 is for bad blocks and also can be a reason for early return. 985 // Should be emitted if kernel tried to output terminating thread. 986 // See proc_task_readdir implementation in Linux. 987 result = Incomplete; 988 } 989 if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9') 990 threads->push_back(internal_atoll(entry->d_name)); 991 } 992 993 // Now we are going to detect short-read or early EOF. In such cases Linux 994 // can return inconsistent list with missing alive threads. 995 // Code will just remember that the list can be incomplete but it will 996 // continue reads to return as much as possible. 997 if (!first_read) { 998 // The first one was a short-read by definition. 999 result = Incomplete; 1000 } else if (read > buffer_.size() - 1024) { 1001 // Read was close to the buffer size. So double the size and assume the 1002 // worst. 1003 buffer_.resize(buffer_.size() * 2); 1004 result = Incomplete; 1005 } else if (!threads->empty() && !IsAlive(threads->back())) { 1006 // Maybe Linux early returned from read on terminated thread (!pid_alive) 1007 // and failed to restore read position. 1008 // See next_tid and proc_task_instantiate in Linux. 1009 result = Incomplete; 1010 } 1011 } 1012 } 1013 1014 bool ThreadLister::IsAlive(int tid) { 1015 // /proc/%d/task/%d/status uses same call to detect alive threads as 1016 // proc_task_readdir. See task_state implementation in Linux. 1017 char path[80]; 1018 internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid); 1019 if (!ReadFileToVector(path, &buffer_) || buffer_.empty()) 1020 return false; 1021 buffer_.push_back(0); 1022 static const char kPrefix[] = "\nPPid:"; 1023 const char *field = internal_strstr(buffer_.data(), kPrefix); 1024 if (!field) 1025 return false; 1026 field += internal_strlen(kPrefix); 1027 return (int)internal_atoll(field) != 0; 1028 } 1029 1030 ThreadLister::~ThreadLister() { 1031 if (!internal_iserror(descriptor_)) 1032 internal_close(descriptor_); 1033 } 1034 #endif 1035 1036 #if SANITIZER_WORDSIZE == 32 1037 // Take care of unusable kernel area in top gigabyte. 1038 static uptr GetKernelAreaSize() { 1039 #if SANITIZER_LINUX && !SANITIZER_X32 1040 const uptr gbyte = 1UL << 30; 1041 1042 // Firstly check if there are writable segments 1043 // mapped to top gigabyte (e.g. stack). 1044 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 1045 if (proc_maps.Error()) 1046 return 0; 1047 MemoryMappedSegment segment; 1048 while (proc_maps.Next(&segment)) { 1049 if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0; 1050 } 1051 1052 #if !SANITIZER_ANDROID 1053 // Even if nothing is mapped, top Gb may still be accessible 1054 // if we are running on 64-bit kernel. 1055 // Uname may report misleading results if personality type 1056 // is modified (e.g. under schroot) so check this as well. 1057 struct utsname uname_info; 1058 int pers = personality(0xffffffffUL); 1059 if (!(pers & PER_MASK) && internal_uname(&uname_info) == 0 && 1060 internal_strstr(uname_info.machine, "64")) 1061 return 0; 1062 #endif // SANITIZER_ANDROID 1063 1064 // Top gigabyte is reserved for kernel. 1065 return gbyte; 1066 #else 1067 return 0; 1068 #endif // SANITIZER_LINUX && !SANITIZER_X32 1069 } 1070 #endif // SANITIZER_WORDSIZE == 32 1071 1072 uptr GetMaxVirtualAddress() { 1073 #if SANITIZER_NETBSD && defined(__x86_64__) 1074 return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE) 1075 #elif SANITIZER_WORDSIZE == 64 1076 # if defined(__powerpc64__) || defined(__aarch64__) 1077 // On PowerPC64 we have two different address space layouts: 44- and 46-bit. 1078 // We somehow need to figure out which one we are using now and choose 1079 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL. 1080 // Note that with 'ulimit -s unlimited' the stack is moved away from the top 1081 // of the address space, so simply checking the stack address is not enough. 1082 // This should (does) work for both PowerPC64 Endian modes. 1083 // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit. 1084 return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1; 1085 #elif SANITIZER_RISCV64 1086 return (1ULL << 38) - 1; 1087 # elif defined(__mips64) 1088 return (1ULL << 40) - 1; // 0x000000ffffffffffUL; 1089 # elif defined(__s390x__) 1090 return (1ULL << 53) - 1; // 0x001fffffffffffffUL; 1091 #elif defined(__sparc__) 1092 return ~(uptr)0; 1093 # else 1094 return (1ULL << 47) - 1; // 0x00007fffffffffffUL; 1095 # endif 1096 #else // SANITIZER_WORDSIZE == 32 1097 # if defined(__s390__) 1098 return (1ULL << 31) - 1; // 0x7fffffff; 1099 # else 1100 return (1ULL << 32) - 1; // 0xffffffff; 1101 # endif 1102 #endif // SANITIZER_WORDSIZE 1103 } 1104 1105 uptr GetMaxUserVirtualAddress() { 1106 uptr addr = GetMaxVirtualAddress(); 1107 #if SANITIZER_WORDSIZE == 32 && !defined(__s390__) 1108 if (!common_flags()->full_address_space) 1109 addr -= GetKernelAreaSize(); 1110 CHECK_LT(reinterpret_cast<uptr>(&addr), addr); 1111 #endif 1112 return addr; 1113 } 1114 1115 #if !SANITIZER_ANDROID 1116 uptr GetPageSize() { 1117 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) && \ 1118 defined(EXEC_PAGESIZE) 1119 return EXEC_PAGESIZE; 1120 #elif SANITIZER_FREEBSD || SANITIZER_NETBSD 1121 // Use sysctl as sysconf can trigger interceptors internally. 1122 int pz = 0; 1123 uptr pzl = sizeof(pz); 1124 int mib[2] = {CTL_HW, HW_PAGESIZE}; 1125 int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0); 1126 CHECK_EQ(rv, 0); 1127 return (uptr)pz; 1128 #elif SANITIZER_USE_GETAUXVAL 1129 return getauxval(AT_PAGESZ); 1130 #else 1131 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy. 1132 #endif 1133 } 1134 #endif // !SANITIZER_ANDROID 1135 1136 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) { 1137 #if SANITIZER_SOLARIS 1138 const char *default_module_name = getexecname(); 1139 CHECK_NE(default_module_name, NULL); 1140 return internal_snprintf(buf, buf_len, "%s", default_module_name); 1141 #else 1142 #if SANITIZER_FREEBSD || SANITIZER_NETBSD 1143 #if SANITIZER_FREEBSD 1144 const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1}; 1145 #else 1146 const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME}; 1147 #endif 1148 const char *default_module_name = "kern.proc.pathname"; 1149 uptr Size = buf_len; 1150 bool IsErr = 1151 (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0); 1152 int readlink_error = IsErr ? errno : 0; 1153 uptr module_name_len = Size; 1154 #else 1155 const char *default_module_name = "/proc/self/exe"; 1156 uptr module_name_len = internal_readlink( 1157 default_module_name, buf, buf_len); 1158 int readlink_error; 1159 bool IsErr = internal_iserror(module_name_len, &readlink_error); 1160 #endif // SANITIZER_SOLARIS 1161 if (IsErr) { 1162 // We can't read binary name for some reason, assume it's unknown. 1163 Report("WARNING: reading executable name failed with errno %d, " 1164 "some stack frames may not be symbolized\n", readlink_error); 1165 module_name_len = internal_snprintf(buf, buf_len, "%s", 1166 default_module_name); 1167 CHECK_LT(module_name_len, buf_len); 1168 } 1169 return module_name_len; 1170 #endif 1171 } 1172 1173 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) { 1174 #if SANITIZER_LINUX 1175 char *tmpbuf; 1176 uptr tmpsize; 1177 uptr tmplen; 1178 if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen, 1179 1024 * 1024)) { 1180 internal_strncpy(buf, tmpbuf, buf_len); 1181 UnmapOrDie(tmpbuf, tmpsize); 1182 return internal_strlen(buf); 1183 } 1184 #endif 1185 return ReadBinaryName(buf, buf_len); 1186 } 1187 1188 // Match full names of the form /path/to/base_name{-,.}* 1189 bool LibraryNameIs(const char *full_name, const char *base_name) { 1190 const char *name = full_name; 1191 // Strip path. 1192 while (*name != '\0') name++; 1193 while (name > full_name && *name != '/') name--; 1194 if (*name == '/') name++; 1195 uptr base_name_length = internal_strlen(base_name); 1196 if (internal_strncmp(name, base_name, base_name_length)) return false; 1197 return (name[base_name_length] == '-' || name[base_name_length] == '.'); 1198 } 1199 1200 #if !SANITIZER_ANDROID 1201 // Call cb for each region mapped by map. 1202 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) { 1203 CHECK_NE(map, nullptr); 1204 #if !SANITIZER_FREEBSD 1205 typedef ElfW(Phdr) Elf_Phdr; 1206 typedef ElfW(Ehdr) Elf_Ehdr; 1207 #endif // !SANITIZER_FREEBSD 1208 char *base = (char *)map->l_addr; 1209 Elf_Ehdr *ehdr = (Elf_Ehdr *)base; 1210 char *phdrs = base + ehdr->e_phoff; 1211 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize; 1212 1213 // Find the segment with the minimum base so we can "relocate" the p_vaddr 1214 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC 1215 // objects have a non-zero base. 1216 uptr preferred_base = (uptr)-1; 1217 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { 1218 Elf_Phdr *phdr = (Elf_Phdr *)iter; 1219 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr) 1220 preferred_base = (uptr)phdr->p_vaddr; 1221 } 1222 1223 // Compute the delta from the real base to get a relocation delta. 1224 sptr delta = (uptr)base - preferred_base; 1225 // Now we can figure out what the loader really mapped. 1226 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { 1227 Elf_Phdr *phdr = (Elf_Phdr *)iter; 1228 if (phdr->p_type == PT_LOAD) { 1229 uptr seg_start = phdr->p_vaddr + delta; 1230 uptr seg_end = seg_start + phdr->p_memsz; 1231 // None of these values are aligned. We consider the ragged edges of the 1232 // load command as defined, since they are mapped from the file. 1233 seg_start = RoundDownTo(seg_start, GetPageSizeCached()); 1234 seg_end = RoundUpTo(seg_end, GetPageSizeCached()); 1235 cb((void *)seg_start, seg_end - seg_start); 1236 } 1237 } 1238 } 1239 #endif 1240 1241 #if SANITIZER_LINUX 1242 #if defined(__x86_64__) 1243 // We cannot use glibc's clone wrapper, because it messes with the child 1244 // task's TLS. It writes the PID and TID of the child task to its thread 1245 // descriptor, but in our case the child task shares the thread descriptor with 1246 // the parent (because we don't know how to allocate a new thread 1247 // descriptor to keep glibc happy). So the stock version of clone(), when 1248 // used with CLONE_VM, would end up corrupting the parent's thread descriptor. 1249 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1250 int *parent_tidptr, void *newtls, int *child_tidptr) { 1251 long long res; 1252 if (!fn || !child_stack) 1253 return -EINVAL; 1254 CHECK_EQ(0, (uptr)child_stack % 16); 1255 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1256 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1257 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1258 register void *r8 __asm__("r8") = newtls; 1259 register int *r10 __asm__("r10") = child_tidptr; 1260 __asm__ __volatile__( 1261 /* %rax = syscall(%rax = SYSCALL(clone), 1262 * %rdi = flags, 1263 * %rsi = child_stack, 1264 * %rdx = parent_tidptr, 1265 * %r8 = new_tls, 1266 * %r10 = child_tidptr) 1267 */ 1268 "syscall\n" 1269 1270 /* if (%rax != 0) 1271 * return; 1272 */ 1273 "testq %%rax,%%rax\n" 1274 "jnz 1f\n" 1275 1276 /* In the child. Terminate unwind chain. */ 1277 // XXX: We should also terminate the CFI unwind chain 1278 // here. Unfortunately clang 3.2 doesn't support the 1279 // necessary CFI directives, so we skip that part. 1280 "xorq %%rbp,%%rbp\n" 1281 1282 /* Call "fn(arg)". */ 1283 "popq %%rax\n" 1284 "popq %%rdi\n" 1285 "call *%%rax\n" 1286 1287 /* Call _exit(%rax). */ 1288 "movq %%rax,%%rdi\n" 1289 "movq %2,%%rax\n" 1290 "syscall\n" 1291 1292 /* Return to parent. */ 1293 "1:\n" 1294 : "=a" (res) 1295 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), 1296 "S"(child_stack), 1297 "D"(flags), 1298 "d"(parent_tidptr), 1299 "r"(r8), 1300 "r"(r10) 1301 : "memory", "r11", "rcx"); 1302 return res; 1303 } 1304 #elif defined(__mips__) 1305 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1306 int *parent_tidptr, void *newtls, int *child_tidptr) { 1307 long long res; 1308 if (!fn || !child_stack) 1309 return -EINVAL; 1310 CHECK_EQ(0, (uptr)child_stack % 16); 1311 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1312 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1313 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1314 register void *a3 __asm__("$7") = newtls; 1315 register int *a4 __asm__("$8") = child_tidptr; 1316 // We don't have proper CFI directives here because it requires alot of code 1317 // for very marginal benefits. 1318 __asm__ __volatile__( 1319 /* $v0 = syscall($v0 = __NR_clone, 1320 * $a0 = flags, 1321 * $a1 = child_stack, 1322 * $a2 = parent_tidptr, 1323 * $a3 = new_tls, 1324 * $a4 = child_tidptr) 1325 */ 1326 ".cprestore 16;\n" 1327 "move $4,%1;\n" 1328 "move $5,%2;\n" 1329 "move $6,%3;\n" 1330 "move $7,%4;\n" 1331 /* Store the fifth argument on stack 1332 * if we are using 32-bit abi. 1333 */ 1334 #if SANITIZER_WORDSIZE == 32 1335 "lw %5,16($29);\n" 1336 #else 1337 "move $8,%5;\n" 1338 #endif 1339 "li $2,%6;\n" 1340 "syscall;\n" 1341 1342 /* if ($v0 != 0) 1343 * return; 1344 */ 1345 "bnez $2,1f;\n" 1346 1347 /* Call "fn(arg)". */ 1348 #if SANITIZER_WORDSIZE == 32 1349 #ifdef __BIG_ENDIAN__ 1350 "lw $25,4($29);\n" 1351 "lw $4,12($29);\n" 1352 #else 1353 "lw $25,0($29);\n" 1354 "lw $4,8($29);\n" 1355 #endif 1356 #else 1357 "ld $25,0($29);\n" 1358 "ld $4,8($29);\n" 1359 #endif 1360 "jal $25;\n" 1361 1362 /* Call _exit($v0). */ 1363 "move $4,$2;\n" 1364 "li $2,%7;\n" 1365 "syscall;\n" 1366 1367 /* Return to parent. */ 1368 "1:\n" 1369 : "=r" (res) 1370 : "r"(flags), 1371 "r"(child_stack), 1372 "r"(parent_tidptr), 1373 "r"(a3), 1374 "r"(a4), 1375 "i"(__NR_clone), 1376 "i"(__NR_exit) 1377 : "memory", "$29" ); 1378 return res; 1379 } 1380 #elif SANITIZER_RISCV64 1381 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1382 int *parent_tidptr, void *newtls, int *child_tidptr) { 1383 if (!fn || !child_stack) 1384 return -EINVAL; 1385 1386 CHECK_EQ(0, (uptr)child_stack % 16); 1387 1388 register int res __asm__("a0"); 1389 register int __flags __asm__("a0") = flags; 1390 register void *__stack __asm__("a1") = child_stack; 1391 register int *__ptid __asm__("a2") = parent_tidptr; 1392 register void *__tls __asm__("a3") = newtls; 1393 register int *__ctid __asm__("a4") = child_tidptr; 1394 register int (*__fn)(void *) __asm__("a5") = fn; 1395 register void *__arg __asm__("a6") = arg; 1396 register int nr_clone __asm__("a7") = __NR_clone; 1397 1398 __asm__ __volatile__( 1399 "ecall\n" 1400 1401 /* if (a0 != 0) 1402 * return a0; 1403 */ 1404 "bnez a0, 1f\n" 1405 1406 // In the child, now. Call "fn(arg)". 1407 "mv a0, a6\n" 1408 "jalr a5\n" 1409 1410 // Call _exit(a0). 1411 "addi a7, zero, %9\n" 1412 "ecall\n" 1413 "1:\n" 1414 1415 : "=r"(res) 1416 : "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__tls), "r"(__ctid), 1417 "r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit) 1418 : "memory"); 1419 return res; 1420 } 1421 #elif defined(__aarch64__) 1422 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1423 int *parent_tidptr, void *newtls, int *child_tidptr) { 1424 long long res; 1425 if (!fn || !child_stack) 1426 return -EINVAL; 1427 CHECK_EQ(0, (uptr)child_stack % 16); 1428 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1429 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1430 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1431 1432 register int (*__fn)(void *) __asm__("x0") = fn; 1433 register void *__stack __asm__("x1") = child_stack; 1434 register int __flags __asm__("x2") = flags; 1435 register void *__arg __asm__("x3") = arg; 1436 register int *__ptid __asm__("x4") = parent_tidptr; 1437 register void *__tls __asm__("x5") = newtls; 1438 register int *__ctid __asm__("x6") = child_tidptr; 1439 1440 __asm__ __volatile__( 1441 "mov x0,x2\n" /* flags */ 1442 "mov x2,x4\n" /* ptid */ 1443 "mov x3,x5\n" /* tls */ 1444 "mov x4,x6\n" /* ctid */ 1445 "mov x8,%9\n" /* clone */ 1446 1447 "svc 0x0\n" 1448 1449 /* if (%r0 != 0) 1450 * return %r0; 1451 */ 1452 "cmp x0, #0\n" 1453 "bne 1f\n" 1454 1455 /* In the child, now. Call "fn(arg)". */ 1456 "ldp x1, x0, [sp], #16\n" 1457 "blr x1\n" 1458 1459 /* Call _exit(%r0). */ 1460 "mov x8, %10\n" 1461 "svc 0x0\n" 1462 "1:\n" 1463 1464 : "=r" (res) 1465 : "i"(-EINVAL), 1466 "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg), 1467 "r"(__ptid), "r"(__tls), "r"(__ctid), 1468 "i"(__NR_clone), "i"(__NR_exit) 1469 : "x30", "memory"); 1470 return res; 1471 } 1472 #elif defined(__powerpc64__) 1473 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1474 int *parent_tidptr, void *newtls, int *child_tidptr) { 1475 long long res; 1476 // Stack frame structure. 1477 #if SANITIZER_PPC64V1 1478 // Back chain == 0 (SP + 112) 1479 // Frame (112 bytes): 1480 // Parameter save area (SP + 48), 8 doublewords 1481 // TOC save area (SP + 40) 1482 // Link editor doubleword (SP + 32) 1483 // Compiler doubleword (SP + 24) 1484 // LR save area (SP + 16) 1485 // CR save area (SP + 8) 1486 // Back chain (SP + 0) 1487 # define FRAME_SIZE 112 1488 # define FRAME_TOC_SAVE_OFFSET 40 1489 #elif SANITIZER_PPC64V2 1490 // Back chain == 0 (SP + 32) 1491 // Frame (32 bytes): 1492 // TOC save area (SP + 24) 1493 // LR save area (SP + 16) 1494 // CR save area (SP + 8) 1495 // Back chain (SP + 0) 1496 # define FRAME_SIZE 32 1497 # define FRAME_TOC_SAVE_OFFSET 24 1498 #else 1499 # error "Unsupported PPC64 ABI" 1500 #endif 1501 if (!fn || !child_stack) 1502 return -EINVAL; 1503 CHECK_EQ(0, (uptr)child_stack % 16); 1504 1505 register int (*__fn)(void *) __asm__("r3") = fn; 1506 register void *__cstack __asm__("r4") = child_stack; 1507 register int __flags __asm__("r5") = flags; 1508 register void *__arg __asm__("r6") = arg; 1509 register int *__ptidptr __asm__("r7") = parent_tidptr; 1510 register void *__newtls __asm__("r8") = newtls; 1511 register int *__ctidptr __asm__("r9") = child_tidptr; 1512 1513 __asm__ __volatile__( 1514 /* fn and arg are saved across the syscall */ 1515 "mr 28, %5\n\t" 1516 "mr 27, %8\n\t" 1517 1518 /* syscall 1519 r0 == __NR_clone 1520 r3 == flags 1521 r4 == child_stack 1522 r5 == parent_tidptr 1523 r6 == newtls 1524 r7 == child_tidptr */ 1525 "mr 3, %7\n\t" 1526 "mr 5, %9\n\t" 1527 "mr 6, %10\n\t" 1528 "mr 7, %11\n\t" 1529 "li 0, %3\n\t" 1530 "sc\n\t" 1531 1532 /* Test if syscall was successful */ 1533 "cmpdi cr1, 3, 0\n\t" 1534 "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t" 1535 "bne- cr1, 1f\n\t" 1536 1537 /* Set up stack frame */ 1538 "li 29, 0\n\t" 1539 "stdu 29, -8(1)\n\t" 1540 "stdu 1, -%12(1)\n\t" 1541 /* Do the function call */ 1542 "std 2, %13(1)\n\t" 1543 #if SANITIZER_PPC64V1 1544 "ld 0, 0(28)\n\t" 1545 "ld 2, 8(28)\n\t" 1546 "mtctr 0\n\t" 1547 #elif SANITIZER_PPC64V2 1548 "mr 12, 28\n\t" 1549 "mtctr 12\n\t" 1550 #else 1551 # error "Unsupported PPC64 ABI" 1552 #endif 1553 "mr 3, 27\n\t" 1554 "bctrl\n\t" 1555 "ld 2, %13(1)\n\t" 1556 1557 /* Call _exit(r3) */ 1558 "li 0, %4\n\t" 1559 "sc\n\t" 1560 1561 /* Return to parent */ 1562 "1:\n\t" 1563 "mr %0, 3\n\t" 1564 : "=r" (res) 1565 : "0" (-1), 1566 "i" (EINVAL), 1567 "i" (__NR_clone), 1568 "i" (__NR_exit), 1569 "r" (__fn), 1570 "r" (__cstack), 1571 "r" (__flags), 1572 "r" (__arg), 1573 "r" (__ptidptr), 1574 "r" (__newtls), 1575 "r" (__ctidptr), 1576 "i" (FRAME_SIZE), 1577 "i" (FRAME_TOC_SAVE_OFFSET) 1578 : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29"); 1579 return res; 1580 } 1581 #elif defined(__i386__) 1582 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1583 int *parent_tidptr, void *newtls, int *child_tidptr) { 1584 int res; 1585 if (!fn || !child_stack) 1586 return -EINVAL; 1587 CHECK_EQ(0, (uptr)child_stack % 16); 1588 child_stack = (char *)child_stack - 7 * sizeof(unsigned int); 1589 ((unsigned int *)child_stack)[0] = (uptr)flags; 1590 ((unsigned int *)child_stack)[1] = (uptr)0; 1591 ((unsigned int *)child_stack)[2] = (uptr)fn; 1592 ((unsigned int *)child_stack)[3] = (uptr)arg; 1593 __asm__ __volatile__( 1594 /* %eax = syscall(%eax = SYSCALL(clone), 1595 * %ebx = flags, 1596 * %ecx = child_stack, 1597 * %edx = parent_tidptr, 1598 * %esi = new_tls, 1599 * %edi = child_tidptr) 1600 */ 1601 1602 /* Obtain flags */ 1603 "movl (%%ecx), %%ebx\n" 1604 /* Do the system call */ 1605 "pushl %%ebx\n" 1606 "pushl %%esi\n" 1607 "pushl %%edi\n" 1608 /* Remember the flag value. */ 1609 "movl %%ebx, (%%ecx)\n" 1610 "int $0x80\n" 1611 "popl %%edi\n" 1612 "popl %%esi\n" 1613 "popl %%ebx\n" 1614 1615 /* if (%eax != 0) 1616 * return; 1617 */ 1618 1619 "test %%eax,%%eax\n" 1620 "jnz 1f\n" 1621 1622 /* terminate the stack frame */ 1623 "xorl %%ebp,%%ebp\n" 1624 /* Call FN. */ 1625 "call *%%ebx\n" 1626 #ifdef PIC 1627 "call here\n" 1628 "here:\n" 1629 "popl %%ebx\n" 1630 "addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n" 1631 #endif 1632 /* Call exit */ 1633 "movl %%eax, %%ebx\n" 1634 "movl %2, %%eax\n" 1635 "int $0x80\n" 1636 "1:\n" 1637 : "=a" (res) 1638 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), 1639 "c"(child_stack), 1640 "d"(parent_tidptr), 1641 "S"(newtls), 1642 "D"(child_tidptr) 1643 : "memory"); 1644 return res; 1645 } 1646 #elif defined(__arm__) 1647 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1648 int *parent_tidptr, void *newtls, int *child_tidptr) { 1649 unsigned int res; 1650 if (!fn || !child_stack) 1651 return -EINVAL; 1652 child_stack = (char *)child_stack - 2 * sizeof(unsigned int); 1653 ((unsigned int *)child_stack)[0] = (uptr)fn; 1654 ((unsigned int *)child_stack)[1] = (uptr)arg; 1655 register int r0 __asm__("r0") = flags; 1656 register void *r1 __asm__("r1") = child_stack; 1657 register int *r2 __asm__("r2") = parent_tidptr; 1658 register void *r3 __asm__("r3") = newtls; 1659 register int *r4 __asm__("r4") = child_tidptr; 1660 register int r7 __asm__("r7") = __NR_clone; 1661 1662 #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__) 1663 # define ARCH_HAS_BX 1664 #endif 1665 #if __ARM_ARCH > 4 1666 # define ARCH_HAS_BLX 1667 #endif 1668 1669 #ifdef ARCH_HAS_BX 1670 # ifdef ARCH_HAS_BLX 1671 # define BLX(R) "blx " #R "\n" 1672 # else 1673 # define BLX(R) "mov lr, pc; bx " #R "\n" 1674 # endif 1675 #else 1676 # define BLX(R) "mov lr, pc; mov pc," #R "\n" 1677 #endif 1678 1679 __asm__ __volatile__( 1680 /* %r0 = syscall(%r7 = SYSCALL(clone), 1681 * %r0 = flags, 1682 * %r1 = child_stack, 1683 * %r2 = parent_tidptr, 1684 * %r3 = new_tls, 1685 * %r4 = child_tidptr) 1686 */ 1687 1688 /* Do the system call */ 1689 "swi 0x0\n" 1690 1691 /* if (%r0 != 0) 1692 * return %r0; 1693 */ 1694 "cmp r0, #0\n" 1695 "bne 1f\n" 1696 1697 /* In the child, now. Call "fn(arg)". */ 1698 "ldr r0, [sp, #4]\n" 1699 "ldr ip, [sp], #8\n" 1700 BLX(ip) 1701 /* Call _exit(%r0). */ 1702 "mov r7, %7\n" 1703 "swi 0x0\n" 1704 "1:\n" 1705 "mov %0, r0\n" 1706 : "=r"(res) 1707 : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7), 1708 "i"(__NR_exit) 1709 : "memory"); 1710 return res; 1711 } 1712 #endif 1713 #endif // SANITIZER_LINUX 1714 1715 #if SANITIZER_LINUX 1716 int internal_uname(struct utsname *buf) { 1717 return internal_syscall(SYSCALL(uname), buf); 1718 } 1719 #endif 1720 1721 #if SANITIZER_ANDROID 1722 #if __ANDROID_API__ < 21 1723 extern "C" __attribute__((weak)) int dl_iterate_phdr( 1724 int (*)(struct dl_phdr_info *, size_t, void *), void *); 1725 #endif 1726 1727 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size, 1728 void *data) { 1729 // Any name starting with "lib" indicates a bug in L where library base names 1730 // are returned instead of paths. 1731 if (info->dlpi_name && info->dlpi_name[0] == 'l' && 1732 info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') { 1733 *(bool *)data = true; 1734 return 1; 1735 } 1736 return 0; 1737 } 1738 1739 static atomic_uint32_t android_api_level; 1740 1741 static AndroidApiLevel AndroidDetectApiLevelStatic() { 1742 #if __ANDROID_API__ <= 19 1743 return ANDROID_KITKAT; 1744 #elif __ANDROID_API__ <= 22 1745 return ANDROID_LOLLIPOP_MR1; 1746 #else 1747 return ANDROID_POST_LOLLIPOP; 1748 #endif 1749 } 1750 1751 static AndroidApiLevel AndroidDetectApiLevel() { 1752 if (!&dl_iterate_phdr) 1753 return ANDROID_KITKAT; // K or lower 1754 bool base_name_seen = false; 1755 dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen); 1756 if (base_name_seen) 1757 return ANDROID_LOLLIPOP_MR1; // L MR1 1758 return ANDROID_POST_LOLLIPOP; // post-L 1759 // Plain L (API level 21) is completely broken wrt ASan and not very 1760 // interesting to detect. 1761 } 1762 1763 extern "C" __attribute__((weak)) void* _DYNAMIC; 1764 1765 AndroidApiLevel AndroidGetApiLevel() { 1766 AndroidApiLevel level = 1767 (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed); 1768 if (level) return level; 1769 level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic() 1770 : AndroidDetectApiLevel(); 1771 atomic_store(&android_api_level, level, memory_order_relaxed); 1772 return level; 1773 } 1774 1775 #endif 1776 1777 static HandleSignalMode GetHandleSignalModeImpl(int signum) { 1778 switch (signum) { 1779 case SIGABRT: 1780 return common_flags()->handle_abort; 1781 case SIGILL: 1782 return common_flags()->handle_sigill; 1783 case SIGTRAP: 1784 return common_flags()->handle_sigtrap; 1785 case SIGFPE: 1786 return common_flags()->handle_sigfpe; 1787 case SIGSEGV: 1788 return common_flags()->handle_segv; 1789 case SIGBUS: 1790 return common_flags()->handle_sigbus; 1791 } 1792 return kHandleSignalNo; 1793 } 1794 1795 HandleSignalMode GetHandleSignalMode(int signum) { 1796 HandleSignalMode result = GetHandleSignalModeImpl(signum); 1797 if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler) 1798 return kHandleSignalExclusive; 1799 return result; 1800 } 1801 1802 #if !SANITIZER_GO 1803 void *internal_start_thread(void *(*func)(void *arg), void *arg) { 1804 // Start the thread with signals blocked, otherwise it can steal user signals. 1805 ScopedBlockSignals block(nullptr); 1806 void *th; 1807 real_pthread_create(&th, nullptr, func, arg); 1808 return th; 1809 } 1810 1811 void internal_join_thread(void *th) { 1812 real_pthread_join(th, nullptr); 1813 } 1814 #else 1815 void *internal_start_thread(void *(*func)(void *), void *arg) { return 0; } 1816 1817 void internal_join_thread(void *th) {} 1818 #endif 1819 1820 #if defined(__aarch64__) 1821 // Android headers in the older NDK releases miss this definition. 1822 #if SANITIZER_LINUX 1823 struct __sanitizer_esr_context { 1824 struct _aarch64_ctx head; 1825 uint64_t esr; 1826 }; 1827 #endif 1828 1829 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) { 1830 #if SANITIZER_LINUX 1831 static const u32 kEsrMagic = 0x45535201; 1832 u8 *aux = reinterpret_cast<u8 *>(ucontext->uc_mcontext.__reserved); 1833 while (true) { 1834 _aarch64_ctx *ctx = (_aarch64_ctx *)aux; 1835 if (ctx->size == 0) break; 1836 if (ctx->magic == kEsrMagic) { 1837 *esr = ((__sanitizer_esr_context *)ctx)->esr; 1838 return true; 1839 } 1840 aux += ctx->size; 1841 } 1842 #endif 1843 return false; 1844 } 1845 #endif 1846 1847 using Context = ucontext_t; 1848 1849 SignalContext::WriteFlag SignalContext::GetWriteFlag() const { 1850 Context *ucontext = (Context *)context; 1851 #if defined(__x86_64__) || defined(__i386__) 1852 static const uptr PF_WRITE = 1U << 1; 1853 #if SANITIZER_FREEBSD 1854 uptr err = ucontext->uc_mcontext.mc_err; 1855 #elif SANITIZER_NETBSD 1856 uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR]; 1857 #elif SANITIZER_SOLARIS && defined(__i386__) 1858 const int Err = 13; 1859 uptr err = ucontext->uc_mcontext.gregs[Err]; 1860 #else 1861 uptr err = ucontext->uc_mcontext.gregs[REG_ERR]; 1862 #endif // SANITIZER_FREEBSD 1863 return err & PF_WRITE ? WRITE : READ; 1864 #elif defined(__mips__) 1865 uint32_t *exception_source; 1866 uint32_t faulty_instruction; 1867 uint32_t op_code; 1868 1869 #if SANITIZER_NETBSD 1870 ucontext_t *nucontext = (ucontext_t *)ucontext; 1871 exception_source = (uint32_t *)_UC_MACHINE_PC(nucontext); 1872 #else 1873 exception_source = (uint32_t *)ucontext->uc_mcontext.pc; 1874 #endif 1875 faulty_instruction = (uint32_t)(*exception_source); 1876 1877 op_code = (faulty_instruction >> 26) & 0x3f; 1878 1879 // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions. 1880 switch (op_code) { 1881 case 0x28: // sb 1882 case 0x29: // sh 1883 case 0x2b: // sw 1884 case 0x3f: // sd 1885 #if __mips_isa_rev < 6 1886 case 0x2c: // sdl 1887 case 0x2d: // sdr 1888 case 0x2a: // swl 1889 case 0x2e: // swr 1890 #endif 1891 return SignalContext::WRITE; 1892 1893 case 0x20: // lb 1894 case 0x24: // lbu 1895 case 0x21: // lh 1896 case 0x25: // lhu 1897 case 0x23: // lw 1898 case 0x27: // lwu 1899 case 0x37: // ld 1900 #if __mips_isa_rev < 6 1901 case 0x1a: // ldl 1902 case 0x1b: // ldr 1903 case 0x22: // lwl 1904 case 0x26: // lwr 1905 #endif 1906 return SignalContext::READ; 1907 #if __mips_isa_rev == 6 1908 case 0x3b: // pcrel 1909 op_code = (faulty_instruction >> 19) & 0x3; 1910 switch (op_code) { 1911 case 0x1: // lwpc 1912 case 0x2: // lwupc 1913 return SignalContext::READ; 1914 } 1915 #endif 1916 } 1917 return SignalContext::UNKNOWN; 1918 #elif defined(__arm__) && !SANITIZER_NETBSD 1919 static const uptr FSR_WRITE = 1U << 11; 1920 uptr fsr = ucontext->uc_mcontext.error_code; 1921 return fsr & FSR_WRITE ? WRITE : READ; 1922 #elif defined(__aarch64__) 1923 static const u64 ESR_ELx_WNR = 1U << 6; 1924 u64 esr; 1925 if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN; 1926 return esr & ESR_ELx_WNR ? WRITE : READ; 1927 #elif defined(__sparc__) 1928 // Decode the instruction to determine the access type. 1929 // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype). 1930 #if SANITIZER_SOLARIS 1931 uptr pc = ucontext->uc_mcontext.gregs[REG_PC]; 1932 #elif SANITIZER_NETBSD 1933 uptr pc = ucontext->uc_mcontext.__gregs[_REG_PC]; 1934 #else 1935 // Historical BSDism here. 1936 struct sigcontext *scontext = (struct sigcontext *)context; 1937 #if defined(__arch64__) 1938 uptr pc = scontext->sigc_regs.tpc; 1939 #else 1940 uptr pc = scontext->si_regs.pc; 1941 #endif 1942 #endif 1943 u32 instr = *(u32 *)pc; 1944 return (instr >> 21) & 1 ? WRITE: READ; 1945 #elif defined(__riscv) 1946 #if SANITIZER_FREEBSD 1947 unsigned long pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc; 1948 #elif SANITIZER_NETBSD 1949 uptr pc = ucontext->uc_mcontext.__gregs[_REG_PC]; 1950 #else 1951 unsigned long pc = ucontext->uc_mcontext.__gregs[REG_PC]; 1952 #endif 1953 unsigned faulty_instruction = *(uint16_t *)pc; 1954 1955 #if defined(__riscv_compressed) 1956 if ((faulty_instruction & 0x3) != 0x3) { // it's a compressed instruction 1957 // set op_bits to the instruction bits [1, 0, 15, 14, 13] 1958 unsigned op_bits = 1959 ((faulty_instruction & 0x3) << 3) | (faulty_instruction >> 13); 1960 unsigned rd = faulty_instruction & 0xF80; // bits 7-11, inclusive 1961 switch (op_bits) { 1962 case 0b10'010: // c.lwsp (rd != x0) 1963 #if __riscv_xlen == 64 1964 case 0b10'011: // c.ldsp (rd != x0) 1965 #endif 1966 return rd ? SignalContext::READ : SignalContext::UNKNOWN; 1967 case 0b00'010: // c.lw 1968 #if __riscv_flen >= 32 && __riscv_xlen == 32 1969 case 0b10'011: // c.flwsp 1970 #endif 1971 #if __riscv_flen >= 32 || __riscv_xlen == 64 1972 case 0b00'011: // c.flw / c.ld 1973 #endif 1974 #if __riscv_flen == 64 1975 case 0b00'001: // c.fld 1976 case 0b10'001: // c.fldsp 1977 #endif 1978 return SignalContext::READ; 1979 case 0b00'110: // c.sw 1980 case 0b10'110: // c.swsp 1981 #if __riscv_flen >= 32 || __riscv_xlen == 64 1982 case 0b00'111: // c.fsw / c.sd 1983 case 0b10'111: // c.fswsp / c.sdsp 1984 #endif 1985 #if __riscv_flen == 64 1986 case 0b00'101: // c.fsd 1987 case 0b10'101: // c.fsdsp 1988 #endif 1989 return SignalContext::WRITE; 1990 default: 1991 return SignalContext::UNKNOWN; 1992 } 1993 } 1994 #endif 1995 1996 unsigned opcode = faulty_instruction & 0x7f; // lower 7 bits 1997 unsigned funct3 = (faulty_instruction >> 12) & 0x7; // bits 12-14, inclusive 1998 switch (opcode) { 1999 case 0b0000011: // loads 2000 switch (funct3) { 2001 case 0b000: // lb 2002 case 0b001: // lh 2003 case 0b010: // lw 2004 #if __riscv_xlen == 64 2005 case 0b011: // ld 2006 #endif 2007 case 0b100: // lbu 2008 case 0b101: // lhu 2009 return SignalContext::READ; 2010 default: 2011 return SignalContext::UNKNOWN; 2012 } 2013 case 0b0100011: // stores 2014 switch (funct3) { 2015 case 0b000: // sb 2016 case 0b001: // sh 2017 case 0b010: // sw 2018 #if __riscv_xlen == 64 2019 case 0b011: // sd 2020 #endif 2021 return SignalContext::WRITE; 2022 default: 2023 return SignalContext::UNKNOWN; 2024 } 2025 #if __riscv_flen >= 32 2026 case 0b0000111: // floating-point loads 2027 switch (funct3) { 2028 case 0b010: // flw 2029 #if __riscv_flen == 64 2030 case 0b011: // fld 2031 #endif 2032 return SignalContext::READ; 2033 default: 2034 return SignalContext::UNKNOWN; 2035 } 2036 case 0b0100111: // floating-point stores 2037 switch (funct3) { 2038 case 0b010: // fsw 2039 #if __riscv_flen == 64 2040 case 0b011: // fsd 2041 #endif 2042 return SignalContext::WRITE; 2043 default: 2044 return SignalContext::UNKNOWN; 2045 } 2046 #endif 2047 default: 2048 return SignalContext::UNKNOWN; 2049 } 2050 #else 2051 (void)ucontext; 2052 return UNKNOWN; // FIXME: Implement. 2053 #endif 2054 } 2055 2056 bool SignalContext::IsTrueFaultingAddress() const { 2057 auto si = static_cast<const siginfo_t *>(siginfo); 2058 // SIGSEGV signals without a true fault address have si_code set to 128. 2059 return si->si_signo == SIGSEGV && si->si_code != 128; 2060 } 2061 2062 void SignalContext::DumpAllRegisters(void *context) { 2063 // FIXME: Implement this. 2064 } 2065 2066 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) { 2067 #if SANITIZER_NETBSD 2068 // This covers all NetBSD architectures 2069 ucontext_t *ucontext = (ucontext_t *)context; 2070 *pc = _UC_MACHINE_PC(ucontext); 2071 *bp = _UC_MACHINE_FP(ucontext); 2072 *sp = _UC_MACHINE_SP(ucontext); 2073 #elif defined(__arm__) 2074 ucontext_t *ucontext = (ucontext_t*)context; 2075 *pc = ucontext->uc_mcontext.arm_pc; 2076 *bp = ucontext->uc_mcontext.arm_fp; 2077 *sp = ucontext->uc_mcontext.arm_sp; 2078 #elif defined(__aarch64__) 2079 ucontext_t *ucontext = (ucontext_t*)context; 2080 *pc = ucontext->uc_mcontext.pc; 2081 *bp = ucontext->uc_mcontext.regs[29]; 2082 *sp = ucontext->uc_mcontext.sp; 2083 #elif defined(__hppa__) 2084 ucontext_t *ucontext = (ucontext_t*)context; 2085 *pc = ucontext->uc_mcontext.sc_iaoq[0]; 2086 /* GCC uses %r3 whenever a frame pointer is needed. */ 2087 *bp = ucontext->uc_mcontext.sc_gr[3]; 2088 *sp = ucontext->uc_mcontext.sc_gr[30]; 2089 #elif defined(__x86_64__) 2090 # if SANITIZER_FREEBSD 2091 ucontext_t *ucontext = (ucontext_t*)context; 2092 *pc = ucontext->uc_mcontext.mc_rip; 2093 *bp = ucontext->uc_mcontext.mc_rbp; 2094 *sp = ucontext->uc_mcontext.mc_rsp; 2095 # else 2096 ucontext_t *ucontext = (ucontext_t*)context; 2097 *pc = ucontext->uc_mcontext.gregs[REG_RIP]; 2098 *bp = ucontext->uc_mcontext.gregs[REG_RBP]; 2099 *sp = ucontext->uc_mcontext.gregs[REG_RSP]; 2100 # endif 2101 #elif defined(__i386__) 2102 # if SANITIZER_FREEBSD 2103 ucontext_t *ucontext = (ucontext_t*)context; 2104 *pc = ucontext->uc_mcontext.mc_eip; 2105 *bp = ucontext->uc_mcontext.mc_ebp; 2106 *sp = ucontext->uc_mcontext.mc_esp; 2107 # else 2108 ucontext_t *ucontext = (ucontext_t*)context; 2109 # if SANITIZER_SOLARIS 2110 /* Use the numeric values: the symbolic ones are undefined by llvm 2111 include/llvm/Support/Solaris.h. */ 2112 # ifndef REG_EIP 2113 # define REG_EIP 14 // REG_PC 2114 # endif 2115 # ifndef REG_EBP 2116 # define REG_EBP 6 // REG_FP 2117 # endif 2118 # ifndef REG_UESP 2119 # define REG_UESP 17 // REG_SP 2120 # endif 2121 # endif 2122 *pc = ucontext->uc_mcontext.gregs[REG_EIP]; 2123 *bp = ucontext->uc_mcontext.gregs[REG_EBP]; 2124 *sp = ucontext->uc_mcontext.gregs[REG_UESP]; 2125 # endif 2126 #elif defined(__powerpc__) || defined(__powerpc64__) 2127 ucontext_t *ucontext = (ucontext_t*)context; 2128 *pc = ucontext->uc_mcontext.regs->nip; 2129 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1]; 2130 // The powerpc{,64}-linux ABIs do not specify r31 as the frame 2131 // pointer, but GCC always uses r31 when we need a frame pointer. 2132 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31]; 2133 #elif defined(__sparc__) 2134 #if defined(__arch64__) || defined(__sparcv9) 2135 #define STACK_BIAS 2047 2136 #else 2137 #define STACK_BIAS 0 2138 # endif 2139 # if SANITIZER_SOLARIS 2140 ucontext_t *ucontext = (ucontext_t *)context; 2141 *pc = ucontext->uc_mcontext.gregs[REG_PC]; 2142 *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS; 2143 #else 2144 // Historical BSDism here. 2145 struct sigcontext *scontext = (struct sigcontext *)context; 2146 #if defined(__arch64__) 2147 *pc = scontext->sigc_regs.tpc; 2148 *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS; 2149 #else 2150 *pc = scontext->si_regs.pc; 2151 *sp = scontext->si_regs.u_regs[14]; 2152 #endif 2153 # endif 2154 *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS; 2155 #elif defined(__mips__) 2156 ucontext_t *ucontext = (ucontext_t*)context; 2157 *pc = ucontext->uc_mcontext.pc; 2158 *bp = ucontext->uc_mcontext.gregs[30]; 2159 *sp = ucontext->uc_mcontext.gregs[29]; 2160 #elif defined(__s390__) 2161 ucontext_t *ucontext = (ucontext_t*)context; 2162 # if defined(__s390x__) 2163 *pc = ucontext->uc_mcontext.psw.addr; 2164 # else 2165 *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff; 2166 # endif 2167 *bp = ucontext->uc_mcontext.gregs[11]; 2168 *sp = ucontext->uc_mcontext.gregs[15]; 2169 #elif defined(__riscv) 2170 ucontext_t *ucontext = (ucontext_t*)context; 2171 # if SANITIZER_FREEBSD 2172 *pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc; 2173 *bp = ucontext->uc_mcontext.mc_gpregs.gp_s[0]; 2174 *sp = ucontext->uc_mcontext.mc_gpregs.gp_sp; 2175 # else 2176 *pc = ucontext->uc_mcontext.__gregs[REG_PC]; 2177 *bp = ucontext->uc_mcontext.__gregs[REG_S0]; 2178 *sp = ucontext->uc_mcontext.__gregs[REG_SP]; 2179 # endif 2180 # elif defined(__hexagon__) 2181 ucontext_t *ucontext = (ucontext_t *)context; 2182 *pc = ucontext->uc_mcontext.pc; 2183 *bp = ucontext->uc_mcontext.r30; 2184 *sp = ucontext->uc_mcontext.r29; 2185 # else 2186 # error "Unsupported arch" 2187 # endif 2188 } 2189 2190 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); } 2191 2192 void InitializePlatformEarly() { 2193 // Do nothing. 2194 } 2195 2196 void MaybeReexec() { 2197 // No need to re-exec on Linux. 2198 } 2199 2200 void CheckASLR() { 2201 #if SANITIZER_NETBSD 2202 int mib[3]; 2203 int paxflags; 2204 uptr len = sizeof(paxflags); 2205 2206 mib[0] = CTL_PROC; 2207 mib[1] = internal_getpid(); 2208 mib[2] = PROC_PID_PAXFLAGS; 2209 2210 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { 2211 Printf("sysctl failed\n"); 2212 Die(); 2213 } 2214 2215 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) { 2216 Printf("This sanitizer is not compatible with enabled ASLR.\n" 2217 "To disable ASLR, please run \"paxctl +a %s\" and try again.\n", 2218 GetArgv()[0]); 2219 Die(); 2220 } 2221 #elif SANITIZER_PPC64V2 2222 // Disable ASLR for Linux PPC64LE. 2223 int old_personality = personality(0xffffffff); 2224 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) { 2225 VReport(1, "WARNING: Program is being run with address space layout " 2226 "randomization (ASLR) enabled which prevents the thread and " 2227 "memory sanitizers from working on powerpc64le.\n" 2228 "ASLR will be disabled and the program re-executed.\n"); 2229 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); 2230 ReExec(); 2231 } 2232 #elif SANITIZER_FREEBSD 2233 int aslr_pie; 2234 uptr len = sizeof(aslr_pie); 2235 #if SANITIZER_WORDSIZE == 64 2236 if (UNLIKELY(internal_sysctlbyname("kern.elf64.aslr.pie_enable", 2237 &aslr_pie, &len, NULL, 0) == -1)) { 2238 // We're making things less 'dramatic' here since 2239 // the OID is not necessarily guaranteed to be here 2240 // just yet regarding FreeBSD release 2241 return; 2242 } 2243 2244 if (aslr_pie > 0) { 2245 Printf("This sanitizer is not compatible with enabled ASLR " 2246 "and binaries compiled with PIE\n"); 2247 Die(); 2248 } 2249 #endif 2250 // there might be 32 bits compat for 64 bits 2251 if (UNLIKELY(internal_sysctlbyname("kern.elf32.aslr.pie_enable", 2252 &aslr_pie, &len, NULL, 0) == -1)) { 2253 return; 2254 } 2255 2256 if (aslr_pie > 0) { 2257 Printf("This sanitizer is not compatible with enabled ASLR " 2258 "and binaries compiled with PIE\n"); 2259 Die(); 2260 } 2261 #else 2262 // Do nothing 2263 #endif 2264 } 2265 2266 void CheckMPROTECT() { 2267 #if SANITIZER_NETBSD 2268 int mib[3]; 2269 int paxflags; 2270 uptr len = sizeof(paxflags); 2271 2272 mib[0] = CTL_PROC; 2273 mib[1] = internal_getpid(); 2274 mib[2] = PROC_PID_PAXFLAGS; 2275 2276 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { 2277 Printf("sysctl failed\n"); 2278 Die(); 2279 } 2280 2281 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) { 2282 Printf("This sanitizer is not compatible with enabled MPROTECT\n"); 2283 Die(); 2284 } 2285 #else 2286 // Do nothing 2287 #endif 2288 } 2289 2290 void CheckNoDeepBind(const char *filename, int flag) { 2291 #ifdef RTLD_DEEPBIND 2292 if (flag & RTLD_DEEPBIND) { 2293 Report( 2294 "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag" 2295 " which is incompatible with sanitizer runtime " 2296 "(see https://github.com/google/sanitizers/issues/611 for details" 2297 "). If you want to run %s library under sanitizers please remove " 2298 "RTLD_DEEPBIND from dlopen flags.\n", 2299 filename, filename); 2300 Die(); 2301 } 2302 #endif 2303 } 2304 2305 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding, 2306 uptr *largest_gap_found, 2307 uptr *max_occupied_addr) { 2308 UNREACHABLE("FindAvailableMemoryRange is not available"); 2309 return 0; 2310 } 2311 2312 bool GetRandom(void *buffer, uptr length, bool blocking) { 2313 if (!buffer || !length || length > 256) 2314 return false; 2315 #if SANITIZER_USE_GETENTROPY 2316 uptr rnd = getentropy(buffer, length); 2317 int rverrno = 0; 2318 if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT) 2319 return false; 2320 else if (rnd == 0) 2321 return true; 2322 #endif // SANITIZER_USE_GETENTROPY 2323 2324 #if SANITIZER_USE_GETRANDOM 2325 static atomic_uint8_t skip_getrandom_syscall; 2326 if (!atomic_load_relaxed(&skip_getrandom_syscall)) { 2327 // Up to 256 bytes, getrandom will not be interrupted. 2328 uptr res = internal_syscall(SYSCALL(getrandom), buffer, length, 2329 blocking ? 0 : GRND_NONBLOCK); 2330 int rverrno = 0; 2331 if (internal_iserror(res, &rverrno) && rverrno == ENOSYS) 2332 atomic_store_relaxed(&skip_getrandom_syscall, 1); 2333 else if (res == length) 2334 return true; 2335 } 2336 #endif // SANITIZER_USE_GETRANDOM 2337 // Up to 256 bytes, a read off /dev/urandom will not be interrupted. 2338 // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom. 2339 uptr fd = internal_open("/dev/urandom", O_RDONLY); 2340 if (internal_iserror(fd)) 2341 return false; 2342 uptr res = internal_read(fd, buffer, length); 2343 if (internal_iserror(res)) 2344 return false; 2345 internal_close(fd); 2346 return true; 2347 } 2348 2349 } // namespace __sanitizer 2350 2351 #endif 2352